Beneficiating weighting agents

Abstract

Beneficiating particulate additives by removing contaminants or minerals that impact the quality and specific gravity of the particulate additives may be achieved via dry solids separation technologies. For example, an air classifier, an electrostatic separator, and a combination thereof may be used to produce a beneficiated particulate additive comprising less than 40% of drill solids by weight of the beneficiated particulate additive.

What is claimed is: 
     
       1. A method comprising:
 treating a wellbore fluid that comprises an aqueous fluid, a particulate additive, and a drill solid by removing the aqueous fluid to produce a dried particulate composition comprising the particulate additive and the drill solid; 
 introducing the dried particulate composition into a dry solids separation system that comprises an air classifier and an electrostatic separator in series; and 
 separating a quantity of the drill solid from the dried particulate composition thereby producing a beneficiated particulate additive, wherein a first portion of drill solid is separated via the air classifier and a second portion of drill solid is separated via the electrostatic separator; 
 wherein the separating with the dry solids separation system that comprises the air classifier and the electrostatic separator in series results in the beneficiated particulate additive:
 i) comprising less than 40% of drill solids by weight of the beneficiated particulate additive, and 
 ii) having a specific gravity greater than the specific gravity of the dried particulate composition. 
 
 
     
     
       2. The method of  claim 1  further comprising:
 centrifuging the wellbore fluid to produce a slurry before producing the dried particulate composition. 
 
     
     
       3. The method of  claim 1 , wherein the beneficiated particulate additive has less than 10% of the drill solids by weight of the beneficiated particulate additive. 
     
     
       4. The method of  claim 1 , wherein the air classifier is a first air classifier, and wherein the dry solids separation system comprises the first air classifier and a second air classifier in series. 
     
     
       5. The method of  claim 1 , wherein the dry solids separation system comprises one air classifier and one electrostatic separator, and wherein the one air classifier is upstream of the one electrostatic separator. 
     
     
       6. The method of  claim 1  further comprising:
 deagglomerating the dried particulate composition before the step of separating. 
 
     
     
       7. The method of  claim 1 
 wherein the dried particulate composition further comprises an oleaginous fluid and wherein the method further comprises heating the dried particulate composition to a temperature sufficient to reduce an amount of the oleaginous fluid before treating the dried particulates composition with the dry solids separation system. 
 
     
     
       8. The method of  claim 1 , wherein the wellbore fluid is a first wellbore fluid and the method further comprises:
 producing a second wellbore fluid with the beneficiated particulate additive. 
 
     
     
       9. The method of  claim 1 , wherein the wellbore fluid comprises an emulsion. 
     
     
       10. The method of  claim 1 , wherein the wellbore fluid further comprises a polyol, an alcohol, an amine, or combinations thereof. 
     
     
       11. The method of  claim 1 , wherein the step of removing the aqueous fluid comprises at least one of thermal desorption, solvent extraction, cryogenic drying, filter-drying, evaporation, crystallization, concentration, or combinations thereof. 
     
     
       12. The method of  claim 1 , wherein the step of treating the wellbore fluid further comprises sedimentation, incline plate separation, or filtration to produce the dried particulate composition. 
     
     
       13. The method of  claim 1 , further comprising heating the dried particulate composition in a thermal treater. 
     
     
       14. The method of  claim 1 , further comprising heating the beneficiated particulate additive in a thermal treater. 
     
     
       15. The method of  claim 1 , wherein the beneficiated particulate additive has a specific gravity of at least 0.05 specific gravity units greater than the dried particulate composition. 
     
     
       16. A method comprising:
 dewatering a wellbore fluid comprising an emulsion of oil and water, a particulate additive, and a drill solid in a liquid solids separation system to produce a slurry comprising a majority of the particulate additive and the drill solid; 
 treating the slurry by at least one of sedimentation, incline plate separation, or filtration to produce a dried particulate composition; 
 introducing the dried particulate composition into a dry solids separation system that comprises an air classifier and an electrostatic separator in series, 
 separating a quantity of the drill solid from the dried particulates thereby producing a beneficiated particulate additive, wherein a first portion of drill solid is separated via the air classifier and a second portion of drill solid is separated via the electrostatic separator; 
 wherein the separating the dry solids separation system that comprises the air classifier and the electrostatic separator in series results in a beneficiated particulate additive:
 i) comprising less than 40% of drill solids by weight of the beneficiated particulate additive, and 
 ii) having a specific gravity greater than the specific gravity of the dried particulate composition. 
 
 
     
     
       17. The method of  claim 16  further comprising centrifuging the wellbore fluid prior to dewatering the wellbore fluid. 
     
     
       18. The method of  claim 16 , further comprising introducing the dried particulate composition into a dryer and deagglomerator. 
     
     
       19. The method of  claim 16 , further comprising heating the dried particulate composition in a thermal treater. 
     
     
       20. The method of  claim 16 , further comprising heating the beneficiated particulate additive in a thermal treater.